Braking

jinhusong
Member
Member
Posts: 171
Joined: March 16th, 2017, 3:34 pm
Division: C
State: CA
Has thanked: 2 times
Been thanked: 2 times

Re: Braking

Post by jinhusong »

Our gravity vehicle is 1.8 kg. Almost no skidding. Time 3.5 seconds, maybe the speed makes big difference. The brake is at rear wheels because our gravity center is quite close to the back end. Every time after stop, we have to use pliers to get the wingnut loose.

We are using 1 3/8 orange wheels with 4 mm rod. They mailed the wrong size wheels, we just decide to take them and try.

Tiger
User avatar
MoMoney$$$;)0)
Member
Member
Posts: 154
Joined: January 14th, 2019, 6:38 pm
Division: C
State: OH
Pronouns: He/Him/His
Has thanked: 41 times
Been thanked: 16 times

Re: Braking

Post by MoMoney$$$;)0) »

jinhusong wrote: February 5th, 2020, 11:54 am Our gravity vehicle is 1.8 kg. Almost no skidding. Time 3.5 seconds, maybe the speed makes big difference. The brake is at rear wheels because our gravity center is quite close to the back end. Every time after stop, we have to use pliers to get the wingnut loose.

We are using 1 3/8 orange wheels with 4 mm rod. They mailed the wrong size wheels, we just decide to take them and try.

Tiger
To be fair, I don't understand why this is an issue. Your vehicle seems to be doing well, since this tight breaking means you have a lot of momentum on your car, and that's a good sign. Moreover, you can probably do even better with testing, but no need for change; just deal with it is what I would recommend. However, if you really want to change this I would suggest lessening the weight of the car as a whole to have less friction on the wheels, or just try not using a wingnut to use for breaking, and maybe try a different type of "mechanism", similar to a wingnut to use.
Division C - Northeast Ohio
Gravity Vehicle
Machines
Detector Building
Circuit Lab
Protein Modeling


2019-2020 Medal Count: 5 :cry:
"Don't be upset by the results you didn't get from the work you didn't do'
Memberships: Builder Cult
User avatar
sciolyperson1
Exalted Member
Exalted Member
Posts: 1074
Joined: April 23rd, 2018, 7:13 pm
Division: C
State: NJ
Pronouns: He/Him/His
Has thanked: 529 times
Been thanked: 601 times
Contact:

Re: Braking

Post by sciolyperson1 »

MoMoney$$$;)0) wrote: February 5th, 2020, 2:46 pm
jinhusong wrote: February 5th, 2020, 11:54 am Our gravity vehicle is 1.8 kg. Almost no skidding. Time 3.5 seconds, maybe the speed makes big difference. The brake is at rear wheels because our gravity center is quite close to the back end. Every time after stop, we have to use pliers to get the wingnut loose.

We are using 1 3/8 orange wheels with 4 mm rod. They mailed the wrong size wheels, we just decide to take them and try.

Tiger
To be fair, I don't understand why this is an issue. Your vehicle seems to be doing well, since this tight breaking means you have a lot of momentum on your car, and that's a good sign. Moreover, you can probably do even better with testing, but no need for change; just deal with it is what I would recommend. However, if you really want to change this I would suggest lessening the weight of the car as a whole to have less friction on the wheels, or just try not using a wingnut to use for breaking, and maybe try a different type of "mechanism", similar to a wingnut to use.
Tight braking was an issue for us with our 2nd buggy, so much so that we actually didn't use that car because it was too fast and the wingnut actually locked onto the stopper. A slower, more consistently stopping one is preferable.

What MoMoney said about the mass on the car is wrong. You never want to reduce friction on the wheels - this is what keeps vertical distance consistent. As jinhusong said, he has almost no skidding - this is probably due to the time being 3.5 seconds, NOT due to his car being 1800g. Try switching out your axle for one with more TPI if possible - this will alleviate forces that lodge the wingnut and stopper together.

I've actually never heard of any stopping mechanism other than a wingnut stopper that works as as consistently as it is. Try sticking with that, don't try anything different (season's already half over).

Hope that helps.
SoCal Planning Team & BirdSO Tournament Director
WW-P HSN '22, Community MS '18
Sciolyperson1's Userpage
User avatar
MTV<=>Operator
Member
Member
Posts: 142
Joined: February 8th, 2019, 12:41 pm
Division: Grad
State: NY
Has thanked: 9 times
Been thanked: 4 times

Re: Braking

Post by MTV<=>Operator »

sciolyperson1 wrote: February 5th, 2020, 4:35 pm
MoMoney$$$;)0) wrote: February 5th, 2020, 2:46 pm
jinhusong wrote: February 5th, 2020, 11:54 am Our gravity vehicle is 1.8 kg. Almost no skidding. Time 3.5 seconds, maybe the speed makes big difference. The brake is at rear wheels because our gravity center is quite close to the back end. Every time after stop, we have to use pliers to get the wingnut loose.

We are using 1 3/8 orange wheels with 4 mm rod. They mailed the wrong size wheels, we just decide to take them and try.

Tiger
To be fair, I don't understand why this is an issue. Your vehicle seems to be doing well, since this tight breaking means you have a lot of momentum on your car, and that's a good sign. Moreover, you can probably do even better with testing, but no need for change; just deal with it is what I would recommend. However, if you really want to change this I would suggest lessening the weight of the car as a whole to have less friction on the wheels, or just try not using a wingnut to use for breaking, and maybe try a different type of "mechanism", similar to a wingnut to use.
Tight braking was an issue for us with our 2nd buggy, so much so that we actually didn't use that car because it was too fast and the wingnut actually locked onto the stopper. A slower, more consistently stopping one is preferable.

What MoMoney said about the mass on the car is wrong. You never want to reduce friction on the wheels - this is what keeps vertical distance consistent. As jinhusong said, he has almost no skidding - this is probably due to the time being 3.5 seconds, NOT due to his car being 1800g. Try switching out your axle for one with more TPI if possible - this will alleviate forces that lodge the wingnut and stopper together.

I've actually never heard of any stopping mechanism other than a wingnut stopper that works as as consistently as it is. Try sticking with that, don't try anything different (season's already half over).

Hope that helps.
What time has your vehicle been getting, if you don't mind sharing? (I see you have been quite successful in this event). It seems as though the main problem with my vehicle is that it goes too fast (2.5 second time). Is there a good way to slow down the vehicle in order to reduce skid? I have the mass concentrated towards the front of my vehicle (where the braking axle is) and it still shifts when the wingnut locks.
THHS '21 Builder Cult Member
2017-2018
2018-2019
2019-2020: GV (9 YUSO, 5 NYC), Detector (8 YUSO, 7 NYC), WS (10 NYC), PPP
2020-2021 Events/ Yosemite/HUSO/River Hill/ NYC South Regional
Vehicle Design / 1/--/--/--
WICI / 3/--/--/--
Circuits /--/ 3/ 5/ 1
Machines /--/ 4/ 2/ 2
Detector /--/--/ 2/--
User avatar
sciolyperson1
Exalted Member
Exalted Member
Posts: 1074
Joined: April 23rd, 2018, 7:13 pm
Division: C
State: NJ
Pronouns: He/Him/His
Has thanked: 529 times
Been thanked: 601 times
Contact:

Re: Braking

Post by sciolyperson1 »

MTV<=>Operator wrote: February 5th, 2020, 4:53 pm
sciolyperson1 wrote: February 5th, 2020, 4:35 pm
MoMoney$$$;)0) wrote: February 5th, 2020, 2:46 pm

To be fair, I don't understand why this is an issue. Your vehicle seems to be doing well, since this tight breaking means you have a lot of momentum on your car, and that's a good sign. Moreover, you can probably do even better with testing, but no need for change; just deal with it is what I would recommend. However, if you really want to change this I would suggest lessening the weight of the car as a whole to have less friction on the wheels, or just try not using a wingnut to use for breaking, and maybe try a different type of "mechanism", similar to a wingnut to use.
Tight braking was an issue for us with our 2nd buggy, so much so that we actually didn't use that car because it was too fast and the wingnut actually locked onto the stopper. A slower, more consistently stopping one is preferable.

What MoMoney said about the mass on the car is wrong. You never want to reduce friction on the wheels - this is what keeps vertical distance consistent. As jinhusong said, he has almost no skidding - this is probably due to the time being 3.5 seconds, NOT due to his car being 1800g. Try switching out your axle for one with more TPI if possible - this will alleviate forces that lodge the wingnut and stopper together.

I've actually never heard of any stopping mechanism other than a wingnut stopper that works as as consistently as it is. Try sticking with that, don't try anything different (season's already half over).

Hope that helps.
What time has your vehicle been getting, if you don't mind sharing? (I see you have been quite successful in this event). It seems as though the main problem with my vehicle is that it goes too fast (2.5 second time). Is there a good way to slow down the vehicle in order to reduce skid? I have the mass concentrated towards the front of my vehicle (where the braking axle is) and it still shifts when the wingnut locks.
Car's 650g (never added weight). 2.964 seconds at MIT.

Slow down the car by lowering your car starting point on the ramp and remove mass from your car to reduce skid and time. Distance is always more important than time.

Usually mass would be added at the back of the car to optimize potential energy - if you can, maybe move it a bit back so it is a 1/3 of the way between the front and back (towards the front).
SoCal Planning Team & BirdSO Tournament Director
WW-P HSN '22, Community MS '18
Sciolyperson1's Userpage
AugustW
Member
Member
Posts: 12
Joined: April 12th, 2019, 8:19 pm
Has thanked: 0
Been thanked: 0

Re: Braking

Post by AugustW »

Can someone send a picture of there breaking system. I don't know how to rebuild a spring breaking system for states without 3d printing. I do not have access to a 3d printer, so I do not know how to make the parts in order to do the spring helped wingnut breaking system. Also, do you have any specific springs to recommend? Thanks.
User avatar
CPScienceDude
Exalted Member
Exalted Member
Posts: 374
Joined: December 12th, 2018, 2:40 pm
Division: Grad
State: IN
Pronouns: He/Him/His
Has thanked: 144 times
Been thanked: 91 times

Re: Braking

Post by CPScienceDude »

AugustW wrote: March 9th, 2020, 10:48 am Can someone send a picture of there breaking system. I don't know how to rebuild a spring breaking system for states without 3d printing. I do not have access to a 3d printer, so I do not know how to make the parts in order to do the spring helped wingnut breaking system. Also, do you have any specific springs to recommend? Thanks.
I'll say it again here, "This isn't a place to ask for pictures of a build. I'll give some suggestions though. For braking, I believe the agreed best right now is a wingnut braking system. See Here."
Crown Point HS '23
Purdue University '27

Assassinator 139 and 147

About Me!
Image
AugustW
Member
Member
Posts: 12
Joined: April 12th, 2019, 8:19 pm
Has thanked: 0
Been thanked: 0

Re: Braking

Post by AugustW »

CPScienceDude wrote: March 9th, 2020, 10:52 am
AugustW wrote: March 9th, 2020, 10:48 am Can someone send a picture of there breaking system. I don't know how to rebuild a spring breaking system for states without 3d printing. I do not have access to a 3d printer, so I do not know how to make the parts in order to do the spring helped wingnut breaking system. Also, do you have any specific springs to recommend? Thanks.
I'll say it again here, "This isn't a place to ask for pictures of a build. I'll give some suggestions though. For braking, I believe the agreed best right now is a wingnut braking system. See Here."
Other people took pictures. Im just looking for advice, no need to overreact. :D :lol: :lol:
viewtopic.php?f=315&t=17063
ndkuma01
Member
Member
Posts: 12
Joined: September 4th, 2019, 3:17 pm
Has thanked: 2 times
Been thanked: 1 time

Re: Braking

Post by ndkuma01 »

I am completely new to the event and new to division C as I am now switching from B to C. And I was reading through the Scioly wiki to get an understanding and I read that the using a wingnut break can have some friction and I wanted to ask if you could use graphite on the nut to reduce friction? I may be getting it wrong be I am just curious and still trying to figure it out.
User avatar
CPScienceDude
Exalted Member
Exalted Member
Posts: 374
Joined: December 12th, 2018, 2:40 pm
Division: Grad
State: IN
Pronouns: He/Him/His
Has thanked: 144 times
Been thanked: 91 times

Re: Braking

Post by CPScienceDude »

ndkuma01 wrote: May 28th, 2020, 5:54 pm I am completely new to the event and new to division C as I am now switching from B to C. And I was reading through the Scioly wiki to get an understanding and I read that the using a wingnut break can have some friction and I wanted to ask if you could use graphite on the nut to reduce friction? I may be getting it wrong be I am just curious and still trying to figure it out.
You certainly can, but I've personally never used it. The friction between two metal surfaces (the nut and the axle) really isn't that impactful to the overall speed of the vehicle. Plus, if your vehicle is too fast it will skid when braking, and you generally want to avoid skid altogether, as it will make it more challenging to accurately aim your vehicle.
These users thanked the author CPScienceDude for the post:
ndkuma01 (May 29th, 2020, 10:50 am)
Crown Point HS '23
Purdue University '27

Assassinator 139 and 147

About Me!
Image
Locked

Return to “Gravity Vehicle C”

Who is online

Users browsing this forum: No registered users and 1 guest